Oxidative stress-mediated effects of angiotensin II in the cardiovascular system

Angiotensin II (Ang II), an endogenous peptide hormone, plays critical roles in the pathophysiological modulation of cardiovascular functions. Ang II is the principle effector of the renin-angiotensin system for maintaining homeostasis in the cardiovascular system, as well as a potent stimulator of NAD(P)H oxidase, which is the major source and primary trigger for reactive oxygen species (ROS) generation in various tissues. Recent accumulating evidence has demonstrated the importance of oxidative stress in Ang II-induced heart diseases. Here, we review the recent progress in the study on oxidative stress-mediated effects of Ang II in the cardiovascular system. In particular, the involvement of Ang II-induced ROS generation in arrhythmias, cell death/heart failure, ischemia/reperfusion injury, cardiac hypertrophy and hypertension are discussed. Ca²⁺/calmodulin-dependent protein kinase II is an important molecule linking Ang II, ROS and cardiovascular pathological conditions.

Hypertensive cardiomyopathy: A clinical approach and literature review

Hypertensive cardiomyopathy (HTN-CM) is a structural cardiac disorder generally accompanied by concentric left ventricular hypertrophy (LVH) associated with diastolic or systolic dysfunction in patients with persistent systemic hypertension. It occurs in the absence of other cardiac diseases capable of causing myocardial hypertrophy or cardiac dysfunction. Persistent systemic hypertension leads to structural and functional myocardial abnormalities resulting in myocardial ischemia, fibrosis, and hypertrophy. HTN-CM is predominantly a disease of impaired relaxation rather than impaired contractility, so patients are usually asymptomatic during resting conditions. However, their stiff left ventricles become incapable of handling increased blood volume and cannot produce appropriate cardiac output with the slight change of circulating volume that may occur during exercise. Importantly, the accompanying LVH is itself a risk factor for mortality and morbidity. Therefore, early detection of LVH development in patients with hypertension (referred to as HTN-CM) is critical for optimal treatment. In addition to pathological findings, echocardiography and cardiac magnetic resonance imaging are ideal tools for the diagnosis of HTN-CM. Timely diagnosis of this condition and utilization of appropriate treatment are required to improve morbidity and mortality in hypertensive patients. This review article presents an overview of the multidimensional impact of myocardial disorder in patients with hypertension. Relevant literature is highlighted and the effects of hypertension on cardiac hypertrophy and heart failure development are discussed, including possible therapeutic options.

Endocrine hypertension: An overview on the current etiopathogenesis and management options

Endocrine causes of secondary hypertension include primary aldosteronism, pheochromocytoma, cushing’s syndrome, hyperparathyroidism and hypo- and hyperthyroidism. They comprise 5%-10% of the causes of secondary hypertension. Primary hyperaldosteronism, the most common of the endocrine cause of hypertension often presents with resistant or difficult to control hypertension associated with either normo-or hypokalemia. Pheochromocytoma, a great mimicker of many conditions, is associated with high morbidity and mortality if left untreated. A complete history including pertinent family history, physical examination along with a high index of suspicion with focused biochemical and radiological evaluation is important to diagnose and effectively treat these conditions. The cost effective targeted genetic screening for current known mutations associated with pheochromocytoma are important for early diagnosis and management in family members. The current review focuses on the most recent evidence regarding causes, clinical features, methods of diagnosis, and management of these conditions. A multidisciplinary approach involving internists, endocrinologists and surgeons is recommended in optimal management of these conditions.

Adipose tissue dysfunction and the pathogenesis of metabolic syndrome

Metabolic syndrome is a growing research area. The underlying mechanisms of metabolic syndrome are still not very clear. Insulin resistance, obesity, inflammation and oxidative stress may play an important role in the pathogenesis of metabolic syndrome. The role of adipose tissue dysfunction is emphasized during the development of obesity. Adipose tissue is identified as a complex endocrine organ and its metabolic functions extend well beyond the classical actions of thermoregulation and of storage and release of fatty acids. Chronic low-grade inflammation activated by the immune system in adipose tissue is a key contributing factor to type 2 diabetes mellitus and cardiovascular diseases. Visceral obesity results in cell autonomous impairment in insulin signaling that leads to insulin resistance. Chronic inflammation in adipose tissue has gained acceptance as a lead promoter of insulin resistance in obesity. Furthermore, obesity creates oxidative stress conditions in adipose tissue that not only correlates with insulin resistance but is also causative in its development. Oxidative stress may be a mechanistic link between several components of metabolic syndrome and cardiovascular diseases, through its role in inflammation and its ability to disrupt insulin-signaling. The study around adipose tissue dysfunction will help to understand the pathogenesis of metabolic syndrome and may bring effective therapy in treatment of metabolic syndrome related diseases. Therefore, this review mainly focuses on the roles of adipose tissue dysfunction in inflammation, insulin resistance, and oxidative stress in the pathogenesis of metabolic syndrome.

Hypertension in children with obesity

The prevalence of obesity related hypertension has dramatically increased in children with the parallel increase in pediatric obesity. This pediatric health problem may adversely affect cardiovascular health in adult life. The pathogenesis of hypertension in obese children is not widely understood. We therefore undertake this review to raise public awareness. Early childhood parameters like birth weight and postnatal weight gain may play important roles in risk for obesity and obesity related hypertension later in childhood and adult life. Further information is required to confirm this origin of hypertension so that appropriate measures are taken in the peri-natal period. The role of sympathetic nervous system has now been well established as one of the principle mechanisms involved in obesity related hypertension. The Renin-Angiotensin system, insulin resistance due to obesity and as a part of metabolic syndrome along with imbalance in adipokines such as leptin and adiponectin, cause activation of the sympathetic system, vasoconstriction, endothelial dysfunction and sodium reabsorption among other perturbations. Multi-step interventions targeting these various mechanisms are required to break the cycle of obesity and metabolic syndrome. Vitamin D deficiency, sleep apnea due to airway obstruction and hyperuricemia may also play a significant role and should not be ignored in its early stages. Obesity is a risk factor for other co-morbid conditions like chronic kidney disease and fatty liver which further accentuate the risk of hypertension. Increased awareness is required to prevent, diagnose and treat obesity related hypertension among the pediatric population.

From hypertension to heart failure

Hypertension is an increasing health problem worldwide especially among the elderly. Its therapeutical importance is indicated by the caused organ damages like hypertensive heart disease (HHD) and heart failure with the subsequent higher morbidity and mortality in the population. In HHD ventricular hypertrophy develops as a compensatory mechanism for pressure overload but as the left ventricular compliance decreases, the process can transform into heart failure with firstly preserved and then into reduced ejection fraction (HFpEF, HFrEF). The main characteristics of underlying mechanisms involve cardiomyocyte growth, vessel changes, increased collagen production in all of which several mechanical stress induced neurohumoral agents, signal transduction pathways are involved. According to the new ESC and AHA guidelines five main groups of antihypertensive agents can be applied for decreasing blood pressure and for the prevention of organ damages. Occasionally, patients are not able to tolerate antihypertensive medication because of side effects, drug intolerance or interactions thus it is more difficult to reach the target blood pressure values. Therefore there are several efforts to complete the existing therapeutical possibilities against the development of organ damages like inhibition of Rho/ROCK pathway (e.g., statins), regulation of ROS formation, influence on mitochondrial biogenesis and enhancing recombinant adenovirus hepatocyte growth factor gene. Hypertension induced oxidative stress causes DNA breaks producing the activation of nuclear poly(ADP-ribose) polymerase-1 (PARP) enzyme that leads to energy depletion and unfavorable modulation of different kinase cascades. PARP activation promotes the development of HHD, and its transition to heart failure. Therefore inhibition of PARP-enzyme offers another new therapeutical approach among hypertensive patients. The purpose of this review is to give a comprehensive summary about the most significant mechanisms in HHD and an insight into new potential therapies.

Clinical implication of hematological indices in the essential hypertension

Prognostic value of haematological indices, especially red cell distribution width, neutrophil lymphocyte ratio and mean platelet volume, was reported with numerous investigations in miscellaneous cardiovascular settings. Their major prognostic value was linked to oxidative stress and inflammation since their level was correlated with major inflammatory markers such as high sensitive C-reactive protein and interleukins. Oxidative stress and chronic inflammation are also postulated as the main pathophysiologic mechanism of essential hypertension (HT) and its vascular complication. Recently, correlation between HT and haematological parameters was searched in numerous studies, which has made the topic more popular. Herein, we reveal the correlation between haematological indices and HT and we also demonstrate the clinical implication of this correlation. Impaired haematological parameters may strongly indicate hypertensive end-organ damage.

Estimated net endogenous acid production and risk of prevalent and incident hypertension in community-dwelling older people

AIM: To investigate the associations of dietary acid-base load with prevalent and incident hypertension in community-living Chinese older adults in Hong Kong.

METHODS: Participants aged ≥ 65 years participating in a cohort study examining the risk factors for osteoporosis completed a validated food frequency questionnaire (FFQ) at baseline between 2001 and 2003. Estimated net endogenous acid production (NEAP) was calculated using Frassetto’s method based on the diet’s protein to potassium ratio derived from the FFQ. Prevalent and 4-year incident hypertension was defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg and/or self-reported use of anti-hypertensive medications. Multivariable logistic regression was used for cross-sectional analysis (n = 3956) to assess the association between estimated NEAP and prevalent hypertension, and for longitudinal analysis (n = 795) on its association with 4-year incident hypertension, with adjustment for various potential socio-demographic and lifestyle factors.

RESULTS: Median estimated NEAP of the participants was 47.7 (interquartile range: 36.2, 60.9) g/mEq. Participants in the highest quartile of energy-adjusted estimated NEAP was associated with increased likelihood of prevalent hypertension than those in the lowest quartile of energy-adjusted estimated NEAP [multivariable OR = 1.66 (95%CI: 1.22 to 2.26, P_trend = 0.002)]. No significant association was observed between energy-adjusted estimated NEAP and risk of incident hypertension.

CONCLUSION: A high dietary acid load was independently associated with an increased likelihood of prevalent hypertension in ambulant older Chinese people in Hong Kong. The longitudinal analyses failed to show any causal relationship between dietary acid load and hypertension in this population.

Seasonal changes in blood pressure: Cardiac and cerebrovascular morbidity and mortality

Cold is a seasonal and circadian risk factor for cardio- and cerebrovascular morbidity and mortality. Colder temperatures have been associated with higher blood pressure (BP), based on studies which show that BP levels measured during the summer months are generally lower than those measured during the winter months. Residents in geographic areas which have greater seasonal temperature differences show greater fluctuation in BP. Surprisingly, atmospheric pressure, rainfall, and humidity were not related to BP levels. The increased sympathetic nervous activity due to cold, as evidenced by elevated BP and by plasma and urinary catecholamines, has been proposed as being the underlying etiology. Patients with heart failure may experience, in cold conditions, endothelial dysfunction and produce fewer endogenous vasodilators (e.g., nitric oxide, prostaglandins) and more endogenous vasoconstrictors (e.g., endothelin), thus increasing afterload. Arterial stiffness is also related to seasonal BP changes. Increased BP, arterial stiffness and endothelial dysfunction could predispose to increased coronary and cerebrovascular events. Improved protection against lower temperatures or increased doses of existing medications or the addition of newer medications could lead to a reduction in increased cardiovascular mortality in winter. Here, we briefly review findings from existing literature and provide an update on seasonal long-term variation in BP along with the related complications.

Progress in neuregulin/ErbB signaling and chronic heart failure

Heart failure is one of the leading causes of death today. It is a complex clinical syndrome in which the heart has a reduced contraction ability and decreased viable myocytes. Novel approaches to the clinical management of heart failure have been achieved through an understanding of the molecular pathways necessary for normal heart development. Neuregulin-1 (NRG-1) has emerged as a potential therapeutic target based on the fact that mice null for NRG-1 or receptors mediating its activity, ErbB2 and ErbB4, are embryonic lethal and exhibit severe cardiac defects. Preclinical studies performed with animal models of heart failure demonstrate that treatment with NRG-1 significantly improves heart function and survival. Clinical data further support NRG-1 as a promising drug candidate for the treatment of cardiac dysfunction in patients. Recent studies have revealed the mechanism underlying the therapeutic effects of NRG-1/ErbB signaling in the treatment of heart failure. Through activation of upstream signaling molecules such as phosphoinositide 3-kinase, mitogen-activated protein kinase, and focal adhesion kinase, NRG-1/ErbB pathway activation results in increased cMLCK expression and enhanced intracellular calcium cycling. The former is a regulator of the contractile machinery, and the latter triggers cell contraction and relaxation. In addition, NRG-1/ErbB signaling also influences energy metabolism and induces epigenetic modification in cardiac myocytes in a way that more closely resembles healthy heart. These observations reveal potentially new treatment options for heart failure.

Self-efficacy for managing hypertension and comorbid conditions

BACKGROUND

Self-efficacy is defined an individual’s belief in completing necessary actions to achieve the desired goal. For individuals with hypertension and other chronic conditions, self-efficacy has been an essential factor to predict adherence to treatment behaviors.

AIM

To examine self-efficacy for managing chronic conditions in individuals with hypertension.

METHODS

A total of 1087 individuals with chronic conditions in two groups (hypertension and non-hypertension groups) were selected in this study. The two groups’ self-efficacy for managing chronic conditions were investigated using the five domains of patient reported outcomes measurement information system self-efficacy for managing chronic conditions measures (PROMIS-SE); daily activities, emotions, medication and treatment, social interactions, and symptoms. Also, the relationships between self-efficacy and other health-related outcomes for the hypertension group were examined using structural equation modeling.

RESULTS

Among 1087 participants, 437 reported having hypertension. The hypertension and non-hypertension groups were statistically different in self-efficacy for managing daily activities [F (1, 598) = 5.63, P < 0.05]. Structural equation modeling indicated that for individuals with hypertension, two domains of PROMIS-SE (managing daily activities and emotions) significantly predict global physical health (P < 0.001 and P < 0.01 sequentially), and one domain (managing emotions) significantly predicts mental health (P < 0.001). Hypertension patients’ general quality of life was significantly predicted by global physical health (P < 0.001) and mental health (P < 0.001).

CONCLUSION

The hypertension group reported deficits in self-efficacy in managing daily activities as compared to the non-hypertension group. In this hypertension group, self-efficacy functioned as an indirect predictor of general quality of life, mediated by global physical and mental health.

RhoA signaling and blood pressure: The consequence of failing to “Tone it Down”

Uncontrolled high blood pressure is a major risk factor for heart attack, stroke, and kidney failure and contributes to an estimated 25% of deaths worldwide. Despite numerous treatment options, estimates project that reasonable blood pressure (BP) control is achieved in only about half of hypertensive patients. Improvements in the detection and management of hypertension will undoubtedly be accomplished through a better understanding of the complex etiology of this disease and a more comprehensive inventory of the genes and genetic variants that influence BP regulation. Recent studies (primarily in pre-clinical models) indicate that the small GTPase RhoA and its downstream target, Rho kinase, play an important role in regulating BP homeostasis. Herein, we summarize the underlying mechanisms and highlight signaling pathways and regulators that impart tight spatial-temporal control of RhoA activity. We also discuss known allelic variations in the RhoA pathway and consider how these polymorphisms may affect genetic risk for hypertension and its clinical manifestations. Finally, we summarize the current (albeit limited) clinical data on the efficacy of targeting the RhoA pathway in hypertensive patients.

Loss of cavin1 and expression of p-caveolin-1 in pulmonary hypertension: Possible role in neointima formation

BACKGROUND

Pulmonary hypertension (PH) is a progressive disease with a high morbidity and mortality rate; and neointima formation leads to the irreversibility of the disease. We have previously reported that in rats, monocrotaline (MCT) injection leads to progressive disruption of endothelial cells (EC), and endothelial caveolin-1 (cav-1) loss, accompanied by the activation of pro-proliferative pathways leading to PH. Four weeks post-MCT, extensive endothelial cav-1 loss is associated with increased cav-1 expression in smooth muscle cells (SMC). Exposing the MCT-treated rats to hypoxia hastens the disease process; and at 4 wk, neointimal lesions and occlusion of the small arteries are observed.

AIM

To identify the alterations that occur during the progression of PH that lead to neointima formation.

METHODS

Male Sprague-Dawley rats (150-175 g) were divided in 4 groups (n = 6-8 per group): controls (C); MCT (M, a single sc injection 40 mg/kg); Hypoxia (H, hypobaric hypoxia); MCT + hypoxia (M+H, MCT-injected rats subjected to hypobaric hypoxia starting on day1). Four weeks later, right ventricular systolic pressure (RVSP), right ventricular hypertrophy (RVH), lung histology, and cav-1 localization using immunofluorescence technique were analyzed. In addition, the expression of cav-1, tyrosine 14 phosphorylated cav-1 (p-cav-1), caveolin-2 (cav-2), cavin-1, vascular endothelial cadherin (VE-Cad) and p-ERK1/2 in the lungs were examined, and the results were compared with the controls.

RESULTS

Significant PH and right ventricular hypertrophy were present in M and H groups [RVSP, mmHg, M 54±5*, H 45±2*, vs C 20±1, P < 0.05; RVH, RV/LV ratio M 0.57±0.02*, H 0.50±0.03*, vs C 0.23±0.007, P < 0.05]; with a further increase in M+H group [RVSP 69±9 mmHg, RV/LV 0.59±0.01 P < 0.05 vs M and H]. All experimental groups revealed medial hypertrophy; but only M+H group exhibited small occluded arteries and neointimal lesions. Immunofluorescence studies revealed endothelial cav-1 loss and increased cav-1 expression in SMC in M group; however, the total cav-1 level in the lungs remained low. In the M+H group, significant endothelial cav-1 loss was associated with increasing expression of cav-1 in SMC; resulting in near normalization of cav-1 levels in the lungs [cav-1, expressed as % control, C 100±0, M 22±4*, H 96±7, M+H 77±6, * = P < 0.05 vs C]. The expression of p-cav-1 was observed in M and M+H groups [M 314±4%, M+H 255±22% P < 0.05 vs C]. Significant loss of cav-2 [% control, C 100±0, M 15±1.4*, H 97±7, M+H 15±2*; M and M+H vs C, * = P < 0.05], cavin-1 [% control, C 100±0, M 20±3*, H 117±7, M+H 20±4*; M and M+H vs C, P < 0.05] and VE-Cad [% control, C 100±0, M 17±4*, H 96±9, M+H 8±3*; M and M+H vs C, P < 0.05] was present in M and M+H groups, confirming extensive disruption of EC. Hypoxia alone did not alter the expression of cav-1 or cav-1 related proteins. Expression of p-ERK1/2 was increased in all 3 PH groups [%control, C 100±0, M 284±23*, H 254±25*, M+H 270±17*; * = P < 0.05 vs C].

CONCLUSION

Both cavin-1 loss and p-cav-1 expression are known to facilitate cell migration; thus, these alterations may in part play a role in neointima formation in PH.

Evidence, hypotheses and significance of MAP kinase TNNI3K interacting with its partners

TNNI3K is a cardiac-specific and cardiac troponin I (cTnI)-interacting MAP kinase, known to play important roles in promoting cardiac differentiation, maintenance of beating rhythm and contractual force. The molecular structure of TNNI3K contains three kinds of domain: a seven or ten NH₂-terminal ankyrin repeat domain followed by a protein kinase domain and a COOH-terminal serine-rich domain. There are many binding sites in the structure of TNNI3K for binding to ATP, magnesium, nucleotide, protein kinase C, antioxidant protein 1 (AOP-1) and cTnI, indicating TNNI3K has many interacting partners. This review summarizes the evidence, hypothesis and significance of TNNI3K interacting with TNNI3 and its other putative interaction partners. From the literature, the interaction partners of TNNI3K are divided into 2 types following their phenotypic pattern of functions, positive interaction (to increase the cardiac performance) or negative interaction (to suppress the cardiac performance). Following their binding sites, it also can be divided into other 2 types: binding to C-terminal domain (e.g., cTnI) or binding to both ankyrin repeat domain and C-terminal domains (AOP-1). To date, a well understood partner of TNNI3K is cTnI, from the molecular structure, physiological function, mechanisms and its significance in some physiological and pathophysiological conditions. There are many reasons to believe that, with more understanding on the TNNI3K interacting with its partners, we can understand more roles of TNNI3K in some cardiac diseases.

Reduction of diastolic blood pressure: Should hypertension guidelines include a lower threshold target?

Reduction of diastolic blood pressure to less than 60-80 mmHg does not improve mortality and may lead to adverse cardiovascular events in high risk patient populations. Despite a growing body of evidence supporting the J-curve phenomenon, no major society guidelines on hypertension include a lower threshold target for diastolic blood pressure. Many major society guidelines for hypertension have been updated in the last 5 years. Some guidelines include goals specific to age and co-morbid conditions. The Sixth Joint Task Force of the European Society of Cardiology and the Canadian Hypertension Education Program are the only guidelines to date that have recommended a lower threshold target, with the Canadian guidelines recommending a caution against diastolic blood pressure less than or equal to 60 mmHg in patients with coronary artery disease. While systolic blood pressure has been proven to be the overriding risk factor in hypertensive patients over the age of 50 years, diastolic blood pressure is an important predictor of mortality in younger adults. Post hoc data analysis of previous clinical trials regarding safe lower diastolic blood pressure threshold remains inconsistent. Randomized clinical trials designed to determine the appropriate diastolic blood pressure targets among different age groups and populations with different comorbidities are warranted. Hypertension guideline goals should be based on an individual’s age, level of risk, and certain co-morbid conditions, especially coronary artery disease, stroke, chronic kidney disease, and diabetes.

Antihypertensive effects of foods

Hypertension is one of the major risk factors for arteriosclerosis, which leads to cardiovascular disease and stroke. Several clinical trials revealed that control of the blood pressure is useful to reduce the morbidity and mortality associated with these diseases. However, the protective efficacy against these complications still remains at less than 50% even if the high blood pressure is treated by current medical drugs. Healthy diets are expected to not only prevent but also treat lifestyle-related diseases. Improvement of the dietary life, including low-salt diets, appropriate alcohol consumption, and calorie restriction, is important for the prevention of hypertension. In addition, green tea, which has been drunk on a daily basis in Japan and China since ancient times, possesses an antihypertensive effect, and it was revealed that its components with this effect are catechins. Many studies have been performed on the antihypertensive effects of foods. Therefore, functional foods and their ingredients, reported to possess antihypertensive effects in animal experiments and human clinical trials, are summarized in this review. Blood pressure might be controlled by improvement of the daily eating habits based on evidence regarding these functional foods, and a healthy longevity can be expected.

Brain inflammation in neurogenic hypertension

One likely mechanism of essential hypertension (EH) is increased sympathoexcitation due to abnormal functions in the cardiovascular center of the brain. Recent findings obtained using experimental animal models of EH have shown that abnormal inflammation in the cardiovascular center may contribute to the onset of hypertension. Inflammatory molecules such as cytokines and reactive oxygen species released from the inflamed vasculature and glial cells in the medulla oblongata and hypothalamus might directly or indirectly affect neuronal functions. This in turn could increase sympathetic nerve activity and consequently arterial pressure. Abnormal inflammatory responses in the brain could also be central mechanisms underlying angiotensin II-related EH. In this review, we present the current understanding of EH mechanisms with regard to inflammatory responses in the cardiovascular center.

Diabetes, diabetic complications, and blood pressure targets

Association of diabetes with hypertension is frequent and it well known that high blood pressure potentiates the probability of diabetic patients to develop macrovascular and microvascular complications. Strong evidence obtained in a number of large scale prospective studies indicates that adequate blood pressure control in diabetic patients is highly beneficial for prevention of cardiovascular events. Nonetheless, only a limited proportion of hypertensive-diabetic individuals included in studies on anti-hypertensive treatment has met the predefined blood pressure goal. The optimal blood pressure goal to be pursued in diabetic patients with hypertension to guarantee effective protection from cardiovascular outcomes is still under intense debate and recommendations of current guidelines on hypertension treatment are still inconsistent. We comment here on the most important studies and conclude that current evidence does not conclusively support the need to reach a blood pressure target in hypertensive patients with diabetes different from nondiabetic hypertensive individuals.

Arterial hypertension, cerebrovascular diseases and dementia

Arterial hypertension (AH) is the most relevant risk factor for acute cerebrovascular disease in general. However, the prevalence of AH is not the same for the different stroke subtypes and is particularly high in lacunar infarcts and atherothrombotic stroke, low in infarcts of unusual cause and undetermined origin, and intermediate in cardioembolic stroke. This risk factor has also been related to vascular dementia and Alzheimer’s disease and their pathological manifestations (senile plaques, neurofibrillary tangles, hippocampal atrophy). The mechanisms linking AH to Alzheimer’s disease remain to be elucidated but some recent studies showed that white matter lesions seen on cerebral magnetic resonance imaging appear to be a good marker of this association. Hypertension-associated pathological changes in the brain and its vasculature include vascular remodelling and impaired cerebral autoregulation like hypoperfusion, ischemia and hypoxia, which may initiate the pathological process of Alzheimer’s disease and the expression of dementia. Therefore, prompt diagnosis and adequate control of hypertension and different vascular risk factors are the rational basis for a more effective strategy in the secondary prevention of cerebrovascular disease and dementia.

Hypertension in low and middle-income countries: Challenges, gaps and limited resources specific strategies

In this article we aim to discuss the burden of hypertension in middle-income countries, the challenges and opportunities, identify some implementation gaps in some of the published initiatives and propose a few pillars that could benefit an upstream population health and health promotion. One billion people suffer from hypertension worldwide; however, the prevalence of hypertension in low and middle-income countries is higher than that in the industrialized countries. Hypertension affects 45% of African adults aged 25 and above, compared to the 36% North American prevalence rate; moreover, the death rate from hypertension in LMICs is higher the than that of the European countries (141 vs 93 per 10000, respectively). The association between increased systolic blood pressure and income reversed between the early 80s and the first decade of the 20^th century; the higher the per capita income the lower the risk of hypertension. Hence, unless an effective interventions, such as improving diagnosis and treatment, lowering salt intake, enhancing access and availability of fresh fruit and vegetable, and increasing leisure time physical activities are implemented, then low income countries epidemic is inevitable. In this article we aim to discuss the global burden of hypertension in low and middle-income countries, the gaps and challenges, identify the high-risk groups and propose a prevention and cost effective treatment strategic framework.

Manidipine: A different dihydropyridine

Blood pressure (BP) plays an important role in the development and progression of cardiovascular disease. Moreover, hypertensive patients often have additional cardiovascular risk factors. Despite the abundance of antihypertensive drug categories, satisfactory BP regulation is often difficult to achieve. A major cause of this difficulty to properly manage BP is the less than optimal adherence of subjects to treatment. This is often due to the various adverse effects of the antihypertensive drugs. Calcium channel blockers (CCB) have an established efficacy for reducing BP. However, their side effect of peripheral edema is often a cause for the discontinuation of treatment. Manidipine holds some unique properties differentiating it from the rest of the CCB class. It has a better safety profile with a lower incidence of peripheral edema. Moreover, there are indications that manidipine holds additional beneficial attributes, such as improvement of renal function and decrease of insulin resistance.

Hypertension in children and adolescents

Pediatric hypertension (HTN) has become the focus of interest recently due to its increasing prevalence. This is mainly related to the increase in childhood obesity, although the current evidence suggests that other lifestyle factors, apart from obesity, contribute to high blood pressure (BP) in childhood. Traditionally, office BP measurements by the physician have been the cornerstone for the assessment of HTN in children. However, since the white coat and masked HTN phenomena are not rare in childhood, out-of-office BP measurements have significantly improved the accurate diagnosis of HTN and decision making. Ambulatory BP monitoring is regarded as indispensable for the evaluation of pediatric HTN, providing details not only for the staging for HTN, but also for the study of other ambulatory BP patterns. It should be pointed out that HTN in children and adolescents is associated with target-organ damage which is significant in terms of cardiovascular risk. The current knowledge, outlined in the present review, is expected to help in early and accurate diagnosis as well as in the management of HTN in children and adolescents.

ARB affects nicotine-induced gene expression profile in human coronary artery endothelial cells

AIM: To investigate the effects of nicotine and nicotine plus angiotensin II receptor blocker (ARB) on the gene expression profile of human coronary artery endothelial cells (HCAECs).

METHODS: The changes in gene expression profiles in HCAECs treated with nicotine and nicotine plus ARB olmesartan were analyzed by DNA microarray. In nicotine-treated HCAECs, 432 genes selected by P < 0.01 were greater than 1.5-fold compared with the untreated cells. Data were analyzed using IPA (Ingenuity^® Systems, www.ingenuity.com).

RESULTS: The gene expression levels of tumor necrosis factor-α, collagen type 1, matrix metalloproteinase-10, and disintegrin and metalloprotease domain 8, which are related to “cardiovascular function and disease”, were significantly increased. In canonical pathway analyses using IPA, “atherosclerosis signaling” was strongly affected by nicotine treatment and this effect was reduced by co-incubation with ARB olmesartan. These data indicate that the deleterious cardiovascular consequences of cigarette smoking may, at least in part, be due to the nicotine-induced gene expression profile related to “atherosclerosis signaling”.

CONCLUSION: The inhibitory effect of ARB against the nicotine-induced gene expression profile may possibly induce anti-atherosclerotic effects that are independent of those from lowering the blood pressure.

Management of hypertension: Current state of the art and challenges

Hypertension is a major modifiable cardiovascular risk factor. Hypertension is also recognized as the most important risk factor for global disease burden. It is well established that a sustained reduction in blood pressure by drugs reduces the incidence of cardiovascular morbidity and mortality. In recent years, studies and new guidelines published for the management of hypertension. Awareness, treatment and control of hypertension are very poor, despite the new guidelines. We highlighted the management of hypertension in the light of current literature.

Contribution of lysosomal cysteine proteases in cardiac and renal diseases

Cardiac and renal diseases (CRDs) are characterized by extensive remodeling of the extracellular matrix (ECM) architecture of the cardiorenal system. Among the many extracellular proteolytic enzymes present in cardiorenal cells and involved in ECM remodeling, members of the matrix metalloproteinase family and serine protease family have received the most attention. However, recent findings from laboratory and clinical studies have indicated that cysteine protease cathepsins also participate in pathogenesis of the heart and kidney. Deficiency and pharmacological inhibition of cathepsins have allowed their in vivo evaluation in the setting of pathological conditions. Furthermore, recent studies evaluating the feasibility of cathepsins as a diagnostic tool have suggested that the serum levels of cathepsins L, S and K and their endogenous inhibitor cystatin C have predictive value as biomarkers in patients with coronary artery disease and heart and renal failure. The goal of this review is to highlight recent discoveries regarding the contributions of cathepsins in CRDs, particularly hypertensive heart failure and proteinuric kidney disease.